Abstract
ACTH cells of the fish Xiphophorus responded to culture on a steroid-free medium by cytological changes that resulted in enlarged, rounded nuclei and enlarged nucleoli. These changes are interpreted as indicating an increase in the activity of the cells. A study of a range of steroids showed that, of the naturally occurring steroids, only cortisol would be effective at physiological concentrations in inhibiting the ACTH cells. Metyrapone and ACTH had no effect on the cells but ICI 33828 resulted in a significant inhibition. The recognition of cortisol by the ACTH cells was found to be a complex one involving several sites on the steroid nucleus. The 11-ketone of cortisone blocked the residual response evoked by 11-deoxycortisol: a similar response would otherwise have been expected from cortisone. The degree of survival of the neurohypophysis had no effect on the ACTH cells and its survival was not necessary for the cells' response to cortisol. It is concluded that at least part of the control of ACTH cells is by a direct negative feedback action of cortisol on the adenohypophysis.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Zeitschrift fur Zellforschung und mikroskopische Anatomie (Vienna, Austria : 1948)
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
